This is a good example of a
‘gear train’. A gear train is usually made up of two or more gears. The
driver in this example is gear ‘A’. If a motor turns gear ‘A’ in an
anticlockwise direction;
Which direction does gear ‘B’ turn ?

So far you have read about ‘driver’ gears, ‘’driven’ gears and gear
trains. An ‘idler’ gear is another important gear. In the example below gear ‘A’ turns in an
anticlockwise direction and also
gear ‘C’ turns in an anticlockwise direction. The ‘idler’ gear is used so
that the rotation of the two important gears is the same.
Is the speed of gears A and B the same ?

In one sentence explain
what an ‘idler’ gears does.

DRAWING GEARS

It would be very difficult to draw gears if you had to draw all the
teeth every time you wanted to design a gear system. For this reason a
gear can be represented by drawing two circles.